task-list.md

@@ -15,8 +15,9 @@ Multi-threading:
 - in first-pass of frame threading with tile threading enabled, it may make sense (assuming no temporal interference from ref_mvs or seg_id) to first parse the tile marked as the one used to update the output CDF, since that would unblock the subsequent thread's pass 1. This is only true if use_ref_mvs=0 and segmentation.temporal_update=0;
 - show_existing_frame will be placed in the frame output queue as something keeping a frame thread busy, meaning for such cases, the frame thread will momentarily stall. This is partially required to prevent overflows of the output queue, or growing it to possibly infinite size on garbage input. But for the regular use case, it makes sense to dis-associate the input and output queue so show-existing-frame does not affect how many frames are actively being processed.
 
-Removing redundancies:
-- the identity_* inverse transforms are stored transposed (as are all other coefficient tables). In all other cases, this saves a transpose in assembly, but for those, it actually means we have to transpose, even though in theory we wouldn't have to at all. Therefore, a potential optimization would be to have a special untransposed zigzag coefficient table and remove the transpose from the assembly, which would make those inverse transforms slightly faster.
+Algorithmic optimizations:
+- the identity_* inverse transforms are stored transposed (as are all other coefficient tables). In all other cases, this saves a transpose in assembly, but for those, it actually means we have to transpose, even though in theory we wouldn't have to at all. Therefore, a potential optimization would be to have a special untransposed zigzag coefficient table and remove the transpose from the assembly, which would make those inverse transforms slightly faster;
+- early exits in C inverse transform code if eob is small (e.g. identity^2).
 
 Cleanups:
 - palette buffers are always 16-bit, even if content is 8-bit (remaining item in #257);